Warn about extract using lots of CPU

jjhenkel · jjhenkel · commit f1b148016edd · 2021-01-22T13:55:11.000-06:00
diff --git a/README.md b/README.md
@@ -27,6 +27,8 @@ To run and evaluate this artifact, you can use on or more of the following comma
 ./shipwright.sh run-rq3
 
 # To extract raw build results 
+# NOTE: this uses many CPU cores during decompression
+# and may take a few minutes to complete
 ./shipwright.sh extract
 ```
 
